Re: Dirty Buffer Writing [was Proposed LogWriter Scheme] - Mailing list pgsql-hackers

From Curtis Faith
Subject Re: Dirty Buffer Writing [was Proposed LogWriter Scheme]
Date
Msg-id DMEEJMCDOJAKPPFACMPMMEFHCEAA.curtis@galtair.com
Whole thread Raw
In response to Re: Dirty Buffer Writing [was Proposed LogWriter Scheme]  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: Dirty Buffer Writing [was Proposed LogWriter Scheme]  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
> This is the trickle syncer.  It prevents bursts of disk activity every
> 30 seconds.  It is for non-fsync writes, of course, and I assume if the
> kernel buffers get low, it starts to flush faster.

AFAICT, the syncer only speeds up when virtual memory paging fills the
buffers past
a threshold and even in that event it only speeds it up by a factor of two.

I can't find any provision for speeding up flushing of the dirty buffers
when they fill for normal file system writes, so I don't think that
happens.

- Curtis



pgsql-hackers by date:

Previous
From: Hannu Krosing
Date:
Subject: Re: Analysis of ganged WAL writes
Next
From: Hannu Krosing
Date:
Subject: Re: Analysis of ganged WAL writes